Radial Nerve Injury
Expert assessment and treatment of radial nerve palsy, wrist drop and complex upper limb nerve injury by Mr Ashley Simpson, Consultant Peripheral Nerve Surgeon.
Anatomy
What Is the Radial Nerve?
The radial nerve is one of the major nerves of the upper limb. It originates from the brachial plexus in the neck and shoulder, travels through the upper arm close to the humerus, crosses the elbow, and supplies key muscles in the forearm and hand.
It controls muscles that straighten the elbow, wrist, fingers and thumb, and provides sensation to the back of the hand and forearm.
Key Clinical Message
A radial nerve injury can profoundly affect hand function, grip, work, sport and daily activities. Early assessment is essential — treatment depends on the site, severity and cause of the injury.
Condition
Radial Nerve Palsy & Symptoms
Radial nerve palsy means loss of radial nerve function — partial or complete. A complete palsy causes inability to extend the wrist, fingers and thumb, and altered sensation over the back of the hand. Grip feels weak because a strong grip depends on the wrist being held in extension.
"Radial nerve palsy is not simply a loss of wrist extension. It affects the whole mechanics of hand function, grip, dexterity and confidence in using the arm." — Mr Ashley Simpson
Wrist Drop
Inability to actively lift the wrist or extend the fingers and thumb.
Weak Grip
Difficulty grasping, typing, writing or lifting objects.
Sensory Symptoms
Numbness, tingling, burning or electric shock sensations over the back of the hand or forearm.
Causes
Common Causes of Radial Nerve Injury
Humeral Shaft Fracture
The nerve runs close to the humerus and may be injured at fracture, during displacement, or during surgery. Some recover spontaneously; others require urgent exploration.
Trauma & Laceration
Cuts, crush injuries, traction, fracture-dislocations and high-energy trauma. Open wounds or progressive deficit require early specialist assessment.
Iatrogenic Injury
Complication of surgery around the shoulder, humerus, elbow or forearm, or after injections and fracture fixation procedures.
Compression
Prolonged pressure, sleep positioning, crutches, tourniquet or tight casts. Often recovers, but persistent palsy should be reviewed.
Posterior Interosseous Nerve
Compression of the deep motor branch near the elbow causes finger and thumb extension weakness, often without sensory symptoms.
Wartenberg's Syndrome
Irritation of the superficial sensory branch causing pain, tingling or numbness over the back of the wrist and hand — without motor weakness.
Localisation
Why the Level of Injury Matters
The pattern of weakness and sensory change helps localise where the nerve has been injured. Correct localisation is essential — prognosis, investigations and treatment options differ depending on which part of the nerve is affected.
High Radial Nerve
Axilla or upper arm. Affects elbow, wrist, finger and thumb extension.
Humeral Level
Associated with humeral shaft fractures. Elbow extension often preserved; wrist, finger and thumb extension weak.
Posterior Interosseous
Deep motor branch. Finger and thumb extension weakness with little or no sensory loss.
Superficial Sensory
Numbness, tingling or neuropathic pain over the back of the hand. No wrist drop.
Diagnosis
Diagnosis & Investigations
Diagnosis begins with a careful history and examination. Mr Simpson assesses the mechanism and timing of injury, the exact pattern of motor and sensory loss, associated fractures or surgical scars, and evidence of recovery. Examination localises the lesion and distinguishes radial nerve palsy from cervical radiculopathy, tendon rupture or central causes.
Radiographs & CT
Fracture pattern, healing, implants and bone position.
Ultrasound
Nerve continuity, compression, neuroma or scar tethering.
MRI / MR Neurography
Muscle denervation, scarring and soft tissue assessment.
Nerve Conduction & EMG
Confirm diagnosis, localise lesion, assess severity and monitor recovery.
Treatment
Treatment: From Splinting to Surgery
1
Initial Management
Wrist extension splint, hand therapy, passive range-of-movement exercises, pain control and clinical monitoring.
2
Nerve Surgery
Exploration, neurolysis, direct repair or nerve grafting when the nerve is divided, trapped or not recovering.
3
Nerve Transfer
A functioning donor nerve branch reinnervates lost muscle groups — considered when direct recovery is unlikely in time.
4
Tendon Transfer
Functioning tendons redirected to restore wrist, finger and thumb extension when nerve reconstruction is no longer possible.
Nerve Injury Severity
Understanding Nerve Injury Severity
Neuropraxia
Nerve structurally intact; conduction temporarily blocked. Recovery over weeks to months.
Axonotmesis
Internal fibres injured; outer structure may be preserved. Recovery depends on slow axonal regeneration and may be incomplete.
Neurotmesis
Nerve severely disrupted or divided. Meaningful spontaneous recovery is unlikely without surgical reconstruction.
"The important questions are where the nerve is injured, how badly it is injured, whether it is recovering, and whether there is a time-sensitive opportunity for reconstruction." — Mr Ashley Simpson
FAQs
Frequently Asked Questions
Can a radial nerve injury recover without surgery?
Yes — compression injuries and some closed fracture-associated palsies can recover spontaneously. The likelihood depends on cause, severity and level of injury.
How long does recovery take?
Weeks, months or longer. More proximal and more severe injuries take longer. Regular clinical review and nerve testing monitor progress.
What is the difference between radial nerve palsy and posterior interosseous nerve palsy?
Radial nerve palsy affects wrist, finger and thumb extension with sensory change. Posterior interosseous palsy mainly affects finger and thumb extension with little or no sensory loss.
Will my hand return to normal?
Some patients recover very well. Severe injuries, delayed treatment and chronic pain can limit recovery. The aim is to restore the best possible function.
Consult Mr Ashley Simpson
Mr Ashley Simpson is a Consultant Peripheral Nerve Surgeon specialising in radial nerve palsy, brachial plexus injury, traumatic and iatrogenic nerve injury. A consultation includes full motor and sensory examination, lesion localisation, review of imaging and electrodiagnostics, and a clear written plan for patients, referrers and therapists.
"The key to radial nerve injury is accurate localisation, careful monitoring and timely reconstruction where needed. Early specialist assessment can make a real difference to long-term hand function." — Mr Ashley Simpson
Patients
Wrist drop, finger or thumb weakness, radial-sided numbness or nerve pain after trauma, fracture or surgery.
Referrers
GPs, physiotherapists, hand therapists, orthopaedic and trauma surgeons, and neurologists are welcome to refer.
Urgent Review
New palsy after surgery, open wounds, progressive deficit or no expected recovery — early review preserves options.
